Multi-Level Indexing: A Better Approach to Tree Indexes
Up to this point, in this lecture, we’ve looked at indexing a file based on building a search tree. However, there are problems with this approach (see previous slide).
Instead, we get back to the notion of the simple indexes we saw earlier in the course, but we extend this notion to that of multi-record indexes and then, multi-level indexes.
While multi-record multi-level indexes really help reduce the number of disk accesses and their overhead space costs are minimal, inserting a new key or deleting an old one is very costly.